In this study, a novel-processing route for producing microcellular zirconia ceramics has been developed. The proposed strategy for making the microcellular zirconia ceramics involves hollow microsphere as a pore former which has extremely low density of $0.025;g/cm^3$. Effects of hollow microsphere content and sintering temperature on microstructure, porosity, pore distribution, and compressive strength were investigated in the processing of microcellular zirconia ceramics. By controlling the content of hollow microsphere, it was possible to make the porous zirconia ceramics with porosities ranging from 45% to 75%. Typical compressive strength value of microcellular zirconia ceramics with ${sim}65%$ porosity was over 50 MPa. By adjusting the mixing ratio of large and small zirconia powders, it was possible to control the pore structure from close to open pores.